Calling All Cows

Last May, tissues from the carcass of a North American cow turned up positive for bovine spongiform encephalopathy–the ailment responsible for mad cow disease. Within hours, the Canadian government traced the animal to the Alberta farm where it had been raised for its 8 years of life. In short order, other members of its herd were quarantined.

What made this possible was Canada's mandatory identification of livestock that are moved off a farm–typically via a tattoo or the more costly implanted computer chip containing data that can be read electronically.

In the United States, by the time cattle reach a butcher, tracing an individual to a herd or farm becomes next to impossible, notes Daniel Andresen of Kansas State University. The vast majority is identified only by an ear tag, which may be changed as the livestock make their way through the beef market from the farms where they're bred, to the ranches where they graze, to the feedlots where they're fattened up in preparation for slaughter. Indeed, many animals reaching the feedlot don't bear an ID tag at all, Andresen notes.

With growing international apprehension over health and bioterrorism threats–such as mad cow disease, foot-and-mouth disease, and anthrax–being able to quickly track the source of an infectious outbreak in livestock could make the difference between containment and epidemic.

Hoping to improve ways of catching disease in time to stop outbreaks, Andresen's team has been developing an electronic device that each cow could wear throughout its life. The equipment could track its location via global-positioning-system (GPS) satellites and monitor the animal's vital signs–all in an electronic form that can be relayed to a farm-based, regional, or even national computer center. The collected data could be used in detailed medical histories of individual animals or as part of a disaster response during a livestock-disease outbreak.

Last month in Cancun, Mexico, at a meeting convened by the Institute of Electrical and Electronics Engineers, the Kansas State team described its progress on what will end up being a 4-year, $1 million project funded by the National Science Foundation. That government agency is financing this research, says Andresen, because it views the project as a contribution to both national security and the science of biomedical-information retrieval.

The experimental package now relies on some $250 worth of parts bundled into a box about the size of a loaf of bread. The heavy power drain of the GPS system contributes to the unit's short battery life of about 3 days.

The package of sensors and electronics rides on a collar or on a belt around the animal's torso. The goal, Andresen says, is to shrink the package "to about the size of a cowbell, something that can be worn around the neck."

The price of each unit would fall with mass production, says Andresen, and the device currently is oversized because the equipment it contains hasn't been fully miniaturized. The scientists have bundled in an accelerometer to indicate when the animal is moving, an oximeter to measure its pulse rate, monitors of other vital signs, the GPS system, and computer chips that store data for several days. The storage capacity is designed to last until the animal strolls by a watering trough, salt lick, or feed station where a wireless unit would download the data.

Some monitors in the package can pick up signals from sensors that might be placed elsewhere in the cow's body. One of the more interesting peripheral units undergoing tests is a $300 core-body-temperature monitor small enough for a cow to swallow. Owing to its weight, the device would fall to the bottom of the animal's rumen, or first stomach, where it could run on battery power for about 9 months. Another temperature sensor is being designed as part of a nose ring. Each time an animal exhaled, it would log an increase in temperature from the animal's warm breath. The pacing of the temperature fluctuations within the nose ring would represent the animal's breathing rate.

Periodically, a rancher could stop by a data-retrieval station to download the accumulated information into a hand-held computer device. Later, those files could be transferred to a farm's main computer to update each animal's medical history.

The Kansas State researchers contend that the devices won't only detect fevers and quickened respiration, but they'll also reveal worrisome behavior such as limited foraging and lethargy. Hopefully, Andresen says early detection of disease from such information will enable ranchers to treat illnesses in a herd before they turn serious. "And if we can even save one veterinarian's visit," he says, "it will pay for one of our systems."

If vets do have to make a call, the digital information in these systems could be relayed into the nationwide livestock-health network that the Agriculture Department and Centers for Disease Control and Prevention use in tracking epidemics. Those agencies in turn might e-mail ranchers with updates about disease outbreaks in their area. Andresen says that such a notice might tell farmers that pneumonia has struck in the next county, "and with the wind now blowing your way, you might want to be on the watch for symptoms, too."

However, Andresen notes, the new sensor package could even pay dividends when animals remain healthy. It will tell a rancher where the cattle have been, "giving him a really good tool for managing the environment, because he now knows what parts of the pasture are likely to be really trampled down and eaten hard." Fencing off those areas could give them time to recover.

Cattle industry remains fragmented

While U.S. chicken and pork operations have become highly centralized, the beef-production industry remains fragmented. And that complicates the record keeping for individual cows. With the Kansas State data system, an animal's medical history could be tracked throughout its life. This should appeal to big meat packers, which could learn which farms and what husbandry practices produce the best beef.

However, selling the advantages of data tracking to individual farmers and ranchers may prove more difficult, Andresen concedes. Many won't like the idea of the government being able to mine data for evidence of disease and then swoop in with inspectors. Other ranchers will worry that environmental officials might decide a cattle operation has more animals than its acreage can ideally support.

Farmers will probably also object to anything that adds even $5 to $10 to their cost per animal, Andresen acknowledges. However, he asserts that if the United States is to continue exporting beef, cattle operations will need to monitor their animals better than they do today. Why? Because Europe is "so much more concerned about things like [mad cow disease] than we are."